DESCRIPTION This proposal seeks support to study a novel multimodal approach to treat patients with advanced non-small cell lung cancer (NSCLC). The approach is to use a combination of non-myelo ablative radioimmunotherapy (RAIT) with taxol platinum based combination chemoradiotherapy. The radioimmunotherapy proposed is an I-131 label anti-CEA antibody. Eligible patients will be those with unresectable Stage I through III non-small cell lung cancer. The specifics of the study will determine the dose limiting toxicities and maximum tolerated dose of the radioimmunotherapy in combination with the single consolidations cycle of cystoplatin/paclitaxel chemotherapy, which will be given after a full course of chemoradiation therapy. A preradioimmunotherapy imaging study will be performing as a comparative study to determine the effect of one concurrent cycle of chemotherapy and radioimmunotherapy on the subsequent pharmacokinetic normal organ and tumor dosimetry. Furthermore, the safety, tolerability and therapeutic impact of this combined multimodal therapy will be assessed. As a secondary objective, the study will follow tumor response that could form a basis for subsequent phase II trial. There is no randomization for the treatment portion of this trial. Patients entered will be treated with a combination of Paclitaxel and Carboplatin with concurrent radiotherapy to a cumulative dose of 60 Gy. Following completion of radiotherapy, paclitaxel/carboplatin chemotherapy will be given in the same doses followed by an injection of 131I labeled antibody directed against the CEA specific epitope.